Most often when an aerosol container is used for spraying of, for example, an insecticide, the container is operated simply by pressing down a button on the top of the container. Then a spring loaded valve in the container is opened by the button allowing the insecticide to flow out through an orifice in the button. The flow continues as long as there is a force applied on the button strong enough to overcome the force of the valve spring and is discontinued when this force is released. However, in some cases it is desired that the aerosol container is kept open for a certain period of time, which can be very cumbersome when the button is manually pressed upon by a finger. Also, in some cases it may be dangerous to remain close to the open container and its out flowing medium for a relatively long period of time. The only hitherto known method to overcome this problem is that the container is provided with a device an actuator, by which the button can be locked in the position where the container is activated. This method is suitable, however, only when it is desired that the entire contents of the container be discharged, because there is no easy way to get the button unlocked once it is locked in the position where the container is open. Nor is there an easy way to change such an aforementioned appurtenance in order to eliminate its defect.